Gear Selector Centreing Spring Broken

[Shiny]

My 2005 MZ1000ST has broken spring. Can I assume this is a part common to other makes? Any help appreciated. Unfortunately the broken off part appears to have dropped into the sump so, until I retrieve it I cannot determine the style.

[Shiny]

Thanks for the link to the parts book. I'm having a local spring manufacturer make up 2. They will be a bigger guage so should last (bike has 47,000 klms).
If anyone needs one I can supply.

[MJ310]

Mine has gone as well, seems to be a common fault, bike works fine and I can select gears but I have to be slow and deliberate. One day I will open it up and have a look. Take a picture and post it.

[Shiny]

MZ Spring.pdf

Gear Selector Centreing Spring

(102.7 KiB) Downloaded 778 times

Hi MJ,

Graham's confirm they have these in stock for a very reasonable 6 - 7 pounds. A huge saving on the $350 my local spring manufacturer wanted.

Here's the part you need;
33 3547306000 Rückholfeder für
Schaltwelle
return spring for shifter.



I found the broken piece in the sump. Tried retrieving through the sump plug hole with a magnet but missed it. Ended up removing the sump (Radiators and exhaust need to come off) which revealed absolutely no metallic material or sludge at all. Nice to know.

To get at the mechanism you need to remove the clutch. I made a special tool from a socket and used a rattle gun to remove the clutch nut/collar.

[boilermaker]

My gear return spring also broke at around 30,000 m. Grahams supplied a new one and I made up a clutch tool from an old socket. Thank god the selector operating system is outside the gearbox. Although the box on this machine can be removed in one piece if I remember rightly.

[MJ310]

Can you tell me what you did to make the clutch tool or show a picture, I will buy a spring next time I am in Taunton.

[Shiny]

33mm I'd is a critical measurement. Used a grinder and a miniature belt sander followed by hand file to finish. Hope this helps.

[MJ310]

Thanks Shiny, I don't have access to a grinder at the moment but I might know someone who has. How thick are the teeth?

[DAVID THOMPSON]

grind it slow so you do not get too hot and ruin the temper

dave

[Shiny]

The posts are approx 5mm wide with approx 20mm between them. Davids right, too much heat might result in the dogs failing due to the rapid power delivered by the rattle gun. It really is worth taking your time, trial fitting as you go.

[billr]

That looks amazingly like a bicycle tool I used to have...don't have that bike any longer( and no idea where the tool wound up...it ain't in the box)

Park 4-prong freewheel tool
That one is only 32mm inside diameter, though.

BillR

[Shiny]

I've been reassembling the clutch following installation of the new gear selector centering spring. I've found that after doing up the centre clutch nut with the rattle gun, it's locked with the basket. On taking some pressure off by slightly unwinding the nut it free's the basket but still is binding.

Went ahead and assembled everything only to find the clutch lever is locked and not actuating the clutch release rod.

Anyone have any ideas? I didn't lock the clutch lever to the handlebar as I didn't think it nessecary.

Not a good day at the office, still great riding weather, so leaving it for the night.

Appreciate any advice.

[Shiny]

Ha! that old extra thin gear behind the main cog driving the clutch not aligned trick.

I don't have the special tool shown in the manual so carefully used a screwdriver to move it into line.

Not sure if this will work as I don't understand the purpose of this thin gear.

Can anyone enlighten me?

[MJ310]

Can't help I'm afraid but it's all useful stuff for when I tackle mine. Keep us informed on what you find.

[Shiny]

Well, after all the nervous-nous around the pretensioned gear behind the clutch cog, the bikes running fine. What a difference a new set of spark plugs has made.